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1.
1.IntroductionInstreamciphers,booleanfunctionf:Z7~ZZhasbeenusedtoproducekeysequences.Butwhichkindofbooleanfunctionisbettertogeneratekeysequencesisnotcertain,andweshouldconsideritaccordingtodifferentcriteria.In[1],C.Mitchellgavesomecriteriaandenumeratedthe…  相似文献   

2.
It is already known that there are several nonlinearity criteria such as algebraic degree, nonlinearity,distance to linear structures, correlation immune, propagationcriterion, differential uniformity,which are used to check whether a cryptographic functionis weak or not. In this paper we will discuss these criteria from a valuation point of view,and consider the largest transformation group which leave a criterion invariant, which isnamed its symmetry group. It can serve as a way of comparing the stability of nonlinearitycriteria under the action of invertible transformations.  相似文献   

3.
1 Introduction and PreliminariesSince the interrelations between the orgachms and the environment seem to be essentialto the system's stabilityll], the effect of diction on the possibility of species coechtence in anecological community has been an haportat subjeCt in population biology. EXcept for someexamples known as ~ive instability or diffusion-induced instability especially in aquaticsystems (see [2]), a diffusion process generally tends to promote stability in ecological systems.Numero…  相似文献   

4.
Roadmapping,originated from industry as a strategic planning tool,is attracting increasing applications in academy.Based on the recognition that roadmapping is a knowledge creation process, this paper analyzes what kind of support is needed or helpful for establishing a creative environment for roadmapping in academy and reviews various types of such support from the perspective of i-system methodology.As case studies of such support,this paper further introduces roadmapping pratices in Janpan Advanced Institute of Science and Technology.  相似文献   

5.
本文在回顾了计算机体系结构的发展历程后,较详细地从六个方面(并行处理、RISC、连接结构、数据库机、五代机、SAA技术)论述了体系结构技术在90年代的发展趋势。  相似文献   

6.
For the discrete dynamical system on the nonnegative orthant generated bya cooperative and concave map T, we present an algebraic criterion of its asymptoticbehavior. The global behavior of such a system is completely determined by the sign of allprincipal minors of the matrix I-DT(0). This criterion applies to the cooperative systemwhich is concave, time-dependent and periodic in t. We give the sufficient conditions thatthe zero solution of such a system is globally asymptotically stable and that it possesses anonzero periodic solution which attracts all initial conditions in the nonnegative orthant.except at the origin. The results of Smith under weaker conditions and some applicationsare included.  相似文献   

7.
InthispaperweinvestigatethespectrumofthetransportoperatorA:Aam=Bac KegwhereBac=--aam(x,v,p)--vZ(x,v)op(x,v,p),Keg=11,joank(x,yip;V',p')op(x,v',p')dp'dy',D(A)={op(x,v,p)ELP(G):;;:t--:,y::op(a,v,--p)=0,for0相似文献   

8.
ONCONVERGENCEANDRATEOFCONVERGENCEOFALGORITHMSINTHEMOVER-STAYERMODELWANGDongqian;Lawoko,C.R.O.(DepartmentofStatistics,MasseyUn...  相似文献   

9.
This paper studies the problem of making an arbitrary discrete system chaotic, or enhancing its existing chaotic behaviors, by designing a universal controller. The only assumption is that the arbitrarily given system has a bounded first derivative in a (small) region of interest.  相似文献   

10.
Increasing popularity of spectrum-based services brings the striking contradictions between the limited spectrum resource and its increasing demands.This paper puts forward an approach to forecast the future spectrum demand and its economic value,so as to offer a scientific basis for spectrum regulators to resolve this contradiction effectively and make a long-term spectrum-use plan.Specifically,this paper analyzes the driving factors of spectrum demand firstly,based on which a forecasting model is constructed to predict the spectrum demand and its deficit/surplus in the next few years.Then,a forecasting model to measure the economic value of spectrum is proposed based on marginal opportunity cost theory,and the indifference curve is introduced to show the economic value generated by additional spectrum.Additionally,an empirical study is conducted to forecast the spectrum demand and its economic value for China in the next 10 years according to the proposed method.The results of this study show that spectrum deficit is a trend in future and releasing additional spectrum will bring China huge economic benefits.  相似文献   

11.
For a Stock Market, the critical problem is the maintenance of its liquidity. Market liquidity can be described in various ways, in particular, in terms of the bid/offer spread and the market depth. Model of market liquidity dynamics has been proposed in Schmidt, A.B.' literate. In our study, we improve his model. On one hand, we think that trading volume is determined by the total number of traders, as well as the relations between the numbers of buyers and sellers, while the model of Schmidt only considers the first, item. On the other hand, Schmidt assumes that the number of "newcomers" in the market is in proportion to the current number of trades. However, we all know that the continual rise or fall of the price will also attract more buyers or sellers, that, is, "newcomers", into the market, which he has not taken for granted. We also prove it, to be a chaos model through analysis of Lyapunov exponent. On the assumption that price variation can be neglected, we discuss the conditions in which chao  相似文献   

12.
CORRECTIONNYSTROMSOLUTIONSOFBIEINPOLYGONALDOMAINONTHEPLANE¥SHIJun(MathematicsDepartment,GraduateSchool,AcademiaSinica,Beijing...  相似文献   

13.
群体排序一致性的逆序数检验法   总被引:2,自引:0,他引:2  
利用逆序数概念给出一种检验群体排序一致性的方法,并从理论上论证了该方法的合理性.  相似文献   

14.
Let x_1,…, x_n be the life spans of n items. Suppose that we start the experi-ment at the time t=0 for all the items simultaneuously aud stop the experiment at the timet=r, where r is a stopping time. The observed data set is Z_n=(x_(1),…, x_(k), r(x)),where x_(i)(i=1,…, n) is the order statistic of x_i, i=1,…, n and k=k(x) is the num-ber of the observed data. Suppose that the distribution family of x_i, i=1,…, n is i.i.d.exponential with life expectation θ>0. For testing the hypothesis H_0: θ≤θ_0 againstH_1: θ>θ_0, we use the total time of experiment S_r=sub from i=1 to k x_(i) +(n-k)r (x) as the teststatistic. We reject H_0 as large value of S_r is observed. In this paper for a given stoppingtime r we construct a stopping time ro so that the resulting test is a best improvement ofthe one, which is based on r, in the sense that the power functions of the two tests are thesame but the test based on r_0 is the one which has the minimnm total experiment time.  相似文献   

15.
1.IntroductionDenotethelifelengthofanyitemofsomekindofproductbyX.ThedistributionfunctionofXisF(t)(F(0)=0).Asiswellknown,themostimportantreliabilitypametersare:(1)R(t)=1--F(t)(reliatiility);(2)tR=tR(F)=sup{t:R(t)2R}(reliablespan);(3)M=M(F)=/ootdF(t)(averagelife).]0Inreliabilityengineeringoneofthemostimportanttasksistoestimatethesereliabilityparameters,especiallytogivegoodlowerconfidencelimitsforthem.Whenitemsofsuchaproductareputintoareliabilitytestitoftenhappensthatnofailureismet.Example…  相似文献   

16.
数据包络分析的灵敏度研究及其应用   总被引:8,自引:0,他引:8  
研究并给出数据包络分析中CCR模型的一种灵敏度分析方法,提出有效决策单元在输入/输出变动时,保持有效性不变的充分条件。实用表明,该法稳定有效。  相似文献   

17.
Given a real-valued separable M-type 2 Banach space X with the p-th power of the norm of C2-class, the almost sure asymptotic upper bounds of the solutions of the Ornstein-Uhlenbeck Processes described by the following equations {dz(t)=A(t,z(t))dt+σ(t,z(t))dW(t),z(0)=z0∈X,are investigated. This study generalizes the corresponding well-known finite dimensional results of Lapeyre (1989) and Mao (1992).  相似文献   

18.
19.
This paper presents a model to describe the dynamic trading process in limit order book. By studying the dynamic pattern of execution probabilities of limit orders with both time and the depth of limit order book, the authors conclude with the following properties: Arrival rates of market buy orders increase as the depth of buy queue in the book increases and decrease as the depth of sell queue increases, and vice versa; similar regularities for the arrival rate of market sell orders; both the arrival rate of market buy order and market sell orders increase as the depth of both sides in the book increases by the same amount. Furthermore the authors describe more detailed temporary and permanent effects of the market depth on the arrival rates of orders.  相似文献   

20.
In this paper, we are devoted to the convergence analysis of algorithms forgeneralized set-valued variational inclusions in Banach spaces. Our results improve, extend,and develop the earlier and recent corresponding results.  相似文献   

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